Method for Reinforcing a Tubular Beam with a Sleeve

ABSTRACT

A method of reinforcing a hollow beam by inserting a sleeve that is held in place by a tang that is placed on a supporting portion of a first or second opening formed in the beam. A fastener is inserted inside the sleeve. A component is attached to the beam by inserting a fastener through the sleeve. An insertion tool may be used to insert the sleeve into the beam.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 12/713,385,filed Feb. 26, 2010, which is a division of U.S. application Ser. No.11/846,194, filed Aug. 28, 2007, now U.S. Pat. No. 7,686,387 issued Mar.30, 2010.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to reinforcing sleeves for tubular beams.

2. Background Art

Attaching heavy components to tubular beams, such as those forming anautomobile chassis, may require a fastener that extends through theentire beam. Attaching a fastener to two walls of a beam provides moresupport for the component than merely fastening the component to asingle wall of the tubular beam.

Tightening a fastener that extends through the tubular beam can deformthe tubular beam. A compressive force is applied to the walls of thetubular beam as the fastener is tightened that may cause the walls to bedeformed and prevent sustainable required torque on the fastener.

A sleeve may be inserted inside the beam to support the walls of thebeam against the compressive force exerted by the fastener on the wallsof the tubular beam. The sleeve may be assembled to an internal portionof the tubular beam by, for instance, welding the sleeve to each beam.However, some components that are attached to beams are for optionalequipment that may not be required. Attaching a sleeve to all beamsincreases the weight and the cost of the tubular beam. It is, therefore,desirable to have a sleeve that can be assembled to the tubular beamwhen needed and omitted when not needed.

The invention as disclosed below addresses the above problems and otherproblems as summarized below.

SUMMARY OF THE INVENTION

In accordance with at least one aspect of the present invention, atubular beam and selectively attached reinforcing sleeve is provided.The first side of the tubular beam has an insertion opening and a firstfastener receiving opening that open into each other. The second sidehas a second fastener receiving opening and a shoulder defining openingthat also open into each other. The reinforcement sleeve includes afastener receiving sleeve portion and a protrusion that holds thereinforcement sleeve in a fastener receiving position within the tubularmember. When the reinforcement sleeve is held in the fastener receivingposition, the fastener receiving sleeve portion is aligned with thefirst and second fastener receiving openings. The protrusion supportsthe reinforcing sleeve on the insertion opening and the shoulderdefining opening. A fastener is inserted through the first fastenerreceiving opening, the fastener receiving sleeve portion and the secondfastener receiving opening.

In at least one implementation, the insertion opening may be wider thanthe first fastener receiving opening, and the shoulder defining openingmay be wider than the second fastener receiving opening. In thisconfiguration, the insertion opening may be large enough to permitinsertion of the reinforcement sleeve into the internal portion of thetubular member. The first and second fastener receiving openings aresmaller than the reinforcement sleeve. The walls of the tubular memberobstruct the reinforcement sleeve from passing through either the firstor second fastener receiving openings.

An upper portion of the shoulder defining opening may form a positioningportion that is substantially aligned with and that has substantiallythe same shape as the insertion opening. When configured in this manner,the positioning portion can provide an open space to facilitate thepositioning of the reinforcement sleeve into the fastener receivingposition.

The reinforcement sleeve may have a plurality of the protrusions. Afirst protrusion may be disposed in close proximity to a first end ofthe reinforcement sleeve and may protrude longitudinally outward fromthe first end. A second protrusion may be disposed in close proximity toa second end of the reinforcement sleeve and may protrude longitudinallyoutward from the second end. A lower portion of the insertion openingmay define an insertion ledge and the lower portion of the shoulderdefining opening may define a shoulder ledge. The insertion ledge andthe shoulder ledge support the respective first and second protrusions.

The first fastener opening may be disposed below the insertion openingand the second fastener opening may be disposed below the shoulderdefining opening. In this configuration, the reinforcement sleeve may beinserted through the insertion opening and lowered into the fastenerreceiving position. The first protrusion is disposed proximate andprotrudes longitudinally outward from a first end of the reinforcementsleeve. The second protrusion may be disposed proximate and protrudelongitudinally outward from a second end of the reinforcement sleeve. Aportion of the first side may support the reinforcement sleeve in thefastener receiving position by engagement with the first protrusion. Aportion of the second side may support the reinforcement sleeve in thefastener receiving position through engagement with the secondprotrusion.

In other implementations, the reinforcement sleeve may include aprojection projecting upwardly and longitudinally outwardly from thereinforcement sleeve. The projection may be disposed at least partiallyoutside of the tubular member when the reinforcement sleeve is disposedin the fastener receiving position. The projection may then engage anouter portion of the tubular member to inhibit the reinforcement sleevefrom falling into the internal portion of the tubular member. Theprojection may project from a top portion of the reinforcement sleeve.The projection may include a perpendicular portion that extends in adirection that is substantially perpendicular to the reinforcementsleeve. The perpendicular portion may be wider than the insertionopening to obstruct it from passing through the insertion opening.

In another embodiment, a reinforcement sleeve for attaching a part to abeam is provided. The beam may have a wall that defines a hollow areainto which the reinforcing sleeve may be assembled between a firstopening and a second opening in the wall. In this embodiment, thereinforcement sleeve includes a sleeve portion that may be insertedbetween the first and second openings and a first hanger portion thatmay be attached to the sleeve portion. The first hanger portion mayengage the wall of the beam to hold a first end of the sleeve inalignment with the first opening. A second hanger portion may also beattached to the sleeve portion to engage the wall of the beam to hold asecond end of the sleeve in alignment with the second opening. The wallmay have a first receptacle adjacent to the first opening to receive thefirst hanger portion. The wall may also have a second receptacleadjacent to the second opening to receive the second hanger portion. Thefirst receptacle may be formed by an insertion opening through which thereinforcement sleeve may be inserted into the beam. The secondreceptacle may be formed by a shoulder opening adjacent to the secondopening. The first hanger portion may be attached to the sleeve portionin close proximity to a first end of the sleeve portion. The secondhanger portion may be attached to the sleeve portion in close proximityto a second end of the reinforcing sleeve.

The reinforcing sleeve may further include a projection attached to thesleeve portion. The projection may engage an outer portion of the wallto prevent the sleeve portion from falling into the hollow area when thereinforcement sleeve is assembled between the first and second openingsin the wall.

A method is provided for reinforcing a closed hollow beam with a sleeveto prevent deformation of the beam when a component is attached to thebeam with a fastener. The sleeve may have at least one tang forsupporting the sleeve on the beam. The beam may have a wall thatencloses a hollow portion. First and second openings in the wall arespaced apart and aligned with each other. The first and second openingsmay each have a supporting portion and a fastener receiving portion thatis narrower than the supporting portion. The method for reinforcing theclosed hollow beam with the sleeve comprises inserting the sleeve intothe hollow portion of the beam through the supporting portion of thefirst opening. The sleeve is positioned to be substantially aligned withthe fastener receiving portion of the first and second openings. Thesleeve is supported by the tang on the supporting portions of the firstand second openings within the hollow portion of the beam. The componentis attached to the beam by inserting the fastener through the fastenerreceiving portion of the first opening, the sleeve, and the fastenerreceiving portion of the second opening.

An insertion tool may be provided. The insertion tool may be configuredto selectively grasp and release the sleeve. The method may furthercomprise the steps of attaching the sleeve to the insertion tool so thatthe insertion tool retains the sleeve. The sleeve is inserted into thehollow portion of the beam with the insertion tool. The sleeve ispositioned to be substantially aligned with the fastener receivingportion of the first and second openings using the insertion tool. Thesleeve is released and the insertion tool is removed.

The insertion tool may have a spring loaded detent or a detent that isactivated by a trigger that selectively grasps and selectively releasesthe sleeve. If so, the method may include the further steps of retainingthe sleeve with the detent of the insertion tool when mounting thesleeve on the insertion tool and pulling the trigger of the insertiontool to retract the detent releasing the sleeve from the insertion tool.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective fragmentary view of an automobile chassisincluding a tubular beam that has an opening for receiving areinforcement sleeve;

FIG. 2 is an enlarged fragmentary perspective view of a portion of thebeam assembly illustrated in FIG. 1 with an attached component in anassembled position;

FIG. 3 is an exploded view of the section of the beam assemblyillustrated in FIG. 2;

FIG. 4 is a cross sectional view taken along the line 4-4 in FIG. 2;

FIG. 5 is a fragmentary side elevational view of the beam assemblyillustrated in FIG. 2;

FIG. 6 is an embodiment of an insertion tool which may be used to inserta reinforcing sleeve into a beam; and

FIG. 7 is a flowchart illustrating an embodiment of a method forinserting a reinforcing sleeve into a beam.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT(S)

Reference will now be made in detail to the illustrated embodiments ofthe present invention which include the best modes of practicing theinvention presently known to the inventors. The following descriptionsare merely exemplary in nature and in no way intended to limit theinvention, its application, or uses. The Figures are not necessarilydrawn to scale. Specific details disclosed herein are not to beinterpreted as limiting, but merely as a representative basis teachingone skilled in the art to variously employ the present invention.

FIG. 1 illustrates an automotive chassis 10 equipped with an embodimentof a tubular beam assembly 12. While the tubular beam assembly 12 isassembled to automotive chassis 10, it should be understood by those ofordinary skill in the art that the tubular beam assembly 12 is notlimited to use in automotive applications. Tubular beam assembly 12 mayalso be used in other vehicles including, without limitation, aircraft,water craft, space craft, and vehicles that travel on rails. Tubularbeam assembly 12 may also be used, without limitation, in applicationssuch as residential and commercial building construction, furnitureconstruction, playground equipment and virtually any other applicationinvolving securing fasteners inside tubular beams. Tubular beam assembly12 allows a user to selectively assemble a reinforcement sleeve inside ahollow tubular beam to inhibit the collapse of the tubular beam when afastener that extends through the tubular beam.

FIG. 2 illustrates a fragmentary perspective view of a portion of thetubular beam assembly 12 of FIG. 1 with an attached component 57 in anassembled position. Attached component 57 has been illustrated incut-away to reveal details of tubular beam assembly 12. FIG. 3illustrates an exploded view of the section of the tubular beam assembly12 illustrated in FIG. 2 without attached component 57. In these views,an interior portion 21 of tubular beam assembly 12 is visible. Tubularbeam assembly 12 includes a tubular member 14 and a reinforcement sleeve16. Tubular member 14 may be made of any suitable material including,without limitation, steel and aluminum. Reinforcement sleeve 16 may bemade of any suitable material including, without limitation, steel andaluminum.

Referring to FIGS. 2 and 3, tubular member 14 includes a first side 18and a second side 20 spaced apart from first side 18 and a substantiallyhollow internal portion or area 21. Tubular member 14 also includes aninsertion opening 22 and a first fastener receiving opening 24 definedwithin first side 18. Tubular member 14 further includes a shoulderdefining opening 26 and a second fastener receiving opening 28 definedwithin second side 20. Tubular member 14 is illustrated as having agenerally rectangular cross section. It should be understood by those ofordinary skill in the art that tubular member 14 may have other crosssectional geometry such as, without limitation, square, circular, andirregularly shaped cross sections.

Insertion opening 22 is wider than first fastener receiving opening 24.Shoulder defining opening 26 is wider than second fastener receivingopening 28. Opening 26 is typically larger than opening 28 to facilitatethe alignment of the sleeve insertion tool, however, opening 26 is smallenough to act as a stop for the sleeve facilitating proper positioningof the sleeve. While insertion opening 22 and first fastener receivingopening 24 are illustrated as distinct, adjoined openings, one ofordinary skill in the art will appreciate that a single opening that isrelatively wide on one side and relatively narrow on an opposite sidemay also be utilized without departing from the teachings of the presentinvention. For example, a triangular shaped opening may be employed. Thesame applies to shoulder defining opening 26 and second fastenerreceiving opening 28.

An insertion ledge 30 is defined by a lower portion of the insertionopening 22. Similarly, a shoulder ledge 32 is defined by a lower portionof the shoulder defining opening 26. The second fastener receivingopening 28 is disposed generally opposite the first fastener receivingopening 24 for receiving a fastener 34 extending through tubular member14.

Fastener 34 has a body portion 36 including threads and a head portion38. In at least one embodiment, the body portion 36 has a diameter thatis less than the width of the first and second fastener receivingopenings. Head portion 38 has a width that exceeds the width of firstfastener receiving opening 24. This dimensional relationship preventsfastener 34 from passing entirely through the first fastener receivingopening 24. Once fastener 34 is disposed within internal portion 21 andextends between the first and second fastener receiving openings 24, 26,fastener 34 may be secured through the use of a nut 40. A washer 42 maybe used to space the nut 40 from the second fastener receiving opening28 and spread the force applied by the nut 40 on the beam 12. Whilefastener 34 is depicted as a threaded bolt cooperating with a nut, oneof ordinary skill in the art will recognize that any suitable fastenermay be used.

Reinforcement sleeve 16 includes a fastener receiving sleeve portion 44having a generally cylindrical shape. The sleeve portion 44 has adiameter that is less than the width of insertion opening 22 but greaterthan the width of the first and second fastener receiving openings 24and 28. This configuration permits reinforcement sleeve 16 to beinserted into tubular member 14 through the insertion opening 22 andlowered into an axially aligned position with first and second fastenerreceiving openings 24 and 28.

Reinforcement sleeve 16 includes a first end 46 and a second end 48disposed approximately opposite first end 46. The first and second ends46 and 48 engage the walls of the beam 12 adjacent the inner side of thefirst and second openings 24 and 28. In this way, the sleeve portionsupports the beam 12.

Reinforcement sleeve 16 further includes a first tang, protrusion orhanger portion 50 and a second tang, protrusion or hanger portion 52disposed proximate the respective first and second ends 46 and 48 of thereinforcement sleeve 16. First tang or protrusion 50 protrudeslongitudinally outwardly beyond first end 46 and second tang orprotrusion 52 extends longitudinally outwardly beyond second end 48. Inthe illustrated embodiment, reinforcement sleeve 16 is formed from asingle sheet of metal that is formed into the fastener receiving sleeveportion 44, a first flange 54 and a second flange 56. As illustrated,the first and second protrusions 50 and 52 are integral with firstflange 54. One of ordinary skill in the art should appreciate that firstand second protrusions 50, 52 could alternatively be separately formedand then attached to the fastener receiving sleeve portion 44.

Reinforcement sleeve 16 further includes a pair of anti-fall-inprojections 58, 60 projecting upwardly and longitudinally outwardly fromthe respective first and second flanges 54 and 56. Upper portions offirst and second anti-fall-in projections 58 and 60 are orientedtransversely with respect to the fastener receiving sleeve portion 44.The respective upper portions of the first and second anti-fall-inprojections 58 and 60 extend longitudinally beyond the first end 46 ofthe reinforcement sleeve 16.

As best illustrated in FIGS. 4 and 5, first and second anti-fall-inprojections 58 and 60 prevent reinforcement sleeve 16 from falling intothe internal portion 21 as reinforcement sleeve 16 is inserted throughinsertion opening 22. The distance between a distal end 59 of the firstanti-fall-in projection 58 to a proximal end 61 of the secondanti-fall-in projection 60 exceeds the width of insertion opening 22.Accordingly, first and second anti-fall-in projections 58 and 60cooperate to obstruct reinforcement sleeve 16 from passing completelythrough insertion opening 22.

First and second anti-fall-in projections 58, 60 are illustrated asbeing integral with first and second flange 54, 56. One of ordinaryskill in the art will recognize that first and second anti-fall-inprojections 58 and 60 may be separately formed and then attached tofastener receiving sleeve portion 44. Additionally, first and secondanti-fall-in projections 58, 60, are illustrated as separate components.In alternate embodiments, first and second anti-fall-in projections 58,60 may comprise a single anti-fall-in projection whose width exceeds thewidth of insertion opening 22.

To position reinforcement sleeve 16 as shown in FIG. 2, reinforcementsleeve 16 may be inserted into tubular member 14 through insertionopening 22 until the fastener receiving sleeve portion 44 passesentirely through insertion opening 22. Reinforcement sleeve 16 may thenbe lowered into a position that is axially aligned with the first andsecond fastener receiving openings 24 and 28, as shown in FIG. 3. Inthis position, first protrusion 50 and second protrusion 52 engageinsertion ledge 30 and shoulder ledge 32, respectively, to supportreinforcement sleeve 16 in a position axially aligned with first andsecond fastener receiving openings 24 and 28. Additional protrusions,such as third protrusion 51 and fourth protrusion 53, may be included tofacilitate the suspension reinforcement sleeve 16 in this position.

One of ordinary skill in the art will appreciate that the first andsecond fastener receiving openings 24 and 28 need not be positionedbelow the insertion opening 22 and the shoulder defining opening 26.Rather, the first and second fastener receiving openings 24, 28 may bepositioned to the side of the respective insertion opening 22 andshoulder defining opening 26. In such an orientation, a person insertingthe reinforcement sleeve 16 into tubular member 14 would insertreinforcement sleeve 16 through the insertion opening 22 and then movereinforcement sleeve 16 to the side. In still other embodiments, theinsertion opening 22 and the shoulder defining opening 26 may bepositioned below the first and second fastener receiving openings 24 and28. In this orientation, the person inserting reinforcement sleeve 16into tubular member 14 would insert reinforcement sleeve 16 throughinsertion opening 22 and then raise reinforcement sleeve 16 into anaxially aligned position adjacent the first and second fastenerreceiving openings 24 and 28.

When fastening the attached component 57 to tubular member 14, thestructural requirements will determine whether the attached component 57can be attached to one face of the tubular member 14 or whether attachedcomponent 57 should be attached to both faces of tubular member 14.Attaching attached component 57 to both faces may be desirable when theload will be relatively heavy. FIG. 2 illustrates one example of how therespective components of the illustrated embodiment may be assembledwhen attaching an attached component 57. In this view, it may beobserved that shoulder defining opening 26 is disposed generallyopposite insertion opening 22. This arrangement provides room tomaneuver reinforcement sleeve 16 after reinforcement sleeve 16 isinserted through insertion opening 22.

FIG. 4 is a cross sectional view taken along the line 4-4 of FIG. 2 thatillustrates the respective positions of the components of tubular beamassembly 12 in their assembled state and attached component 57.Reinforcement sleeve 16 extends through the internal portion 21 oftubular member 14 from first side 18 to second side 20. Attachedcomponent 57 is positioned adjacent tubular member 14 and the fastener34 passes through an opening in attached component 57 and throughinsertion opening 22. Fastener 34 is received within the fastenerreceiving sleeve portion 44 and protrudes through the second fastenerreceiving opening 28, and through an opposite end of attached component57. Attached component 57 may have in integral nut to receive fastener34. Alternatively, a separate nut 40 and washer 42 may be utilized. Anut and washer that is integral with, or pre-attached to attachedcomponent 57 may be desirable when a back portion of tubular member 14is inaccessible.

When fastened, fastener 34 is tightened against outer portions of firstside 18 and second side 20. First and second ends 46 and 48 of thefastener receiving sleeve portion 44 support internal portions of sides18 and 20 to inhibit them from collapsing inwardly as fastener 34 istightened. FIG. 4 also illustrates the cooperation between the first andsecond protrusions 50, 52 with insertion ledge 30 and shoulder ledge 32,respectively. Additionally, an upper portion of the first anti-fall-inprojection 58 can be seen disposed substantially adjacent to an outerportion of first side 18 where it may engage the outer portion of firstside 18 to prevent the reinforcement sleeve 16 from falling intointernal portion 21.

FIG. 5 is a fragmentary side elevational view of the tubular beamassembly 12 with reinforcement sleeve 16 inserted into the internalportion 21 of the tubular member 14. First and third protrusions 50, 51engage the insertion ledge 30 to support the fastener receiving sleeveportion 44 in a position substantially axially aligned with firstfastener receiving opening 24. First anti-fall-in projection 58 andsecond anti-fall-in projection 60 are shown in engagement with the firstside 18 of the tubular member 14 to prevent the reinforcement sleeve 16from falling into the internal portion 21. FIG. 5 shows the relationshipbetween the diameter of the fastener receiving sleeve portion 44 (shownin phantom lines) and the first fastener receiving opening 24. Thediameter of the fastener receiving sleeve portion 44 exceeds the widthof the first fastener receiving opening 24. As a result, thereinforcement sleeve 16 is inhibited from sliding out of the tubularmember 14 once the fastener receiving sleeve portion 44 is substantiallyaligned with the first fastener receiving opening 24. The reinforcementsleeve also supports the tubular member 14, as previously described.

FIG. 6 illustrates an embodiment of an insertion tool which may be usedto insert the reinforcement sleeve 16 into the tubular member 14. Theinsertion tool 62 has a handle portion 64 to allow manipulation ofinsertion tool 62 by a user. Reinforcement sleeve 16 may be positionedon the insertion tool 62 such that the first end 46 of the reinforcementsleeve 16 would rest against a back stop 66 and the second end of thereinforcement sleeve 16 would be held in position by a detent 68. Thedetent may be a spring loaded protrusion that obstructs movement of thereinforcement sleeve 16 until sufficient force is applied to overcomethe force of the spring. In other embodiments, a trigger 74 may beincluded proximate handle portion 64 to allow a user to remotely releasethe reinforcement sleeve 16 by depressing the trigger 74. The trigger 74may be operatively connected to the detent 68 by a movable core element(not shown).

In at least one embodiment, the length L from the back stop 66 to thedetent would be approximately equal to the length of the reinforcementsleeve 16. To prevent the reinforcement sleeve 16 from dangling looselyon insertion tool 62, a thickened portion 70 may be provided. Thickenedportion 70 may have a diameter that is only slightly less than aninternal diameter of reinforcement sleeve 16 to more securely holdreinforcement sleeve 16. Insertion tool 62 may further include a roundedend 72 opposite from the handle portion 64. Rounded end 72 may assist auser in inserting the reinforcement sleeve 16 into tubular member 14 inconditions of limited visibility or access. Rounded end 72 is narrowenough to pass from shoulder defining opening 26 into second fastenerreceiving opening 28.

FIG. 7 contains a flowchart illustrating an embodiment of a method forassembling reinforcement sleeve 16 to tubular member 14. A userassembles the reinforcement sleeve 16 onto the insertion tool 62 suchthat the first end 46 abuts against back stop 66 and second end 48passes over detent 68 and is prevented from sliding off insertion tool62 by detent 68.

With the reinforcement sleeve 16 positioned on insertion tool 62,insertion tool 62 is inserted into tubular member 14 through theinsertion opening 22. The rounded end 72 can be used to find theshoulder defining opening 26. The insertion tool may be further insertedthrough the insertion opening 22 until the first end 46 passes throughinsertion opening 22. Using insertion tool 62, the reinforcement sleeve16 may be lowered into a position that is substantially aligned with thefirst and second fastener receiving openings 24 and 28. The first andthird protrusions engage the insertion ledge 30 and with the second andfourth protrusions 51 and 53 engaging the shoulder ledge 32. Insertiontool 62 may be pulled out of reinforcement sleeve 16. Enough forceshould be used to overcome the force exerted by the spring loaded detent68. If the insertion tool 62 is equipped with trigger 74, then thedetent 68 may be retracted using trigger 74. Once the insertion tool 62is removed from the reinforcement sleeve 16 and from tubular member 14,a component may be attached to the tubular beam assembly 12 by insertinga fastener 34 through the first fastener receiving opening 24, thefastener receiving sleeve portion 44 and the second fastener receivingopening 28.

While the best mode for carrying out the invention has been described indetail, those familiar with the art to which this invention relates willrecognize various alternative designs and embodiments for practicing theinvention as defined by the following claims.

1. A reinforcement sleeve for attaching a part to a beam, the beamhaving a wall that defines a hollow area into which the reinforcementsleeve may be assembled between a first opening and a second opening inthe wall, the reinforcement sleeve comprising: a sleeve portion insertedbetween the first and second openings; and a first hanger portionattached to the sleeve portion that engages the wall of the beam to holda first end of the sleeve in alignment with the first opening and asecond hanger portion attached to the sleeve portion that engages thewall of the beam to hold a second end of the sleeve in alignment withthe second opening.
 2. The reinforcement sleeve of claim 1 wherein thewall has a first receptacle adjacent the first opening that receives thefirst hanger portion and a second receptacle adjacent the second openingthat receives the second hanger portion.
 3. The reinforcement sleeve ofclaim 2 wherein the first receptacle is formed by an insertion openingthrough which the reinforcement sleeve is inserted into the beam and thesecond receptacle is formed by a shoulder opening adjacent to the secondopening.
 4. The reinforcement sleeve of claim 2 wherein the first hangerportion is attached to the sleeve portion proximate a first end of thesleeve portion and wherein the second hanger portion is attached to thesleeve portion proximate a second end of the reinforcement sleeve. 5.The reinforcement sleeve of claim 1 further comprising a projectionattached to the sleeve portion, the projection engaging an outer portionof the wall to prevent the sleeve portion from falling into the hollowarea when the reinforcement sleeve is assembled between the first andsecond openings in the wall.